Conveyor idler assembly



y 1, 1962 A. J. KlNDlG 3,031,895

CONVEYOR IDLER ASSEMBLY Original Filed Sept. 28, 1953 NVENTOR' (3 IURNIEJ.' |ND1C3 3,031,895 CONVEYOR IDLER ASSEMBLY Arme J. Kindig,Coiumhus, Ohio, assignor, by masne assignments, to Jeirey GaionManufacturing Company, a co'poration of Ohio Continuation of applicationSer. No. 382,736, Sept. 28, 1953. This application Mar. 26, 1957, Ser.No. 648527 1 claim. (Ci 74-230.7)

This invention relates to conveyor idlers which are adapted to supportan endless conveyor belt, and more particularly to the assembly of thebelt supporting wheel with the shaft of the conveyor idler.

This application is a continn-ation of patent application, Serial No.382,73 6, filed on September 28, 1953, for a Multi-Wheeled Conveyor Rolland Wheel Therefor, now abandoned.

It is a prime object of the instant invention to provide improved wheeland shaft assembly for a conveyor 1 er.

It is a further object of the instant nvention to provide an improvedwheel and shaft assembly for a con-veyor idler in which the wheel isadapted to be force-fitted on the shaft and secured in place on theshaft by an interference fit between the wheel and the shaft.

It is another object of the instant invention to provide a novel wheeland shaft assembly for a oonveyor idler in which the wheel is formed ofresilient material and comprises a non-extensible, rigid cylindricalband embedded in the material of the wheel, and in which some of thematerial of the wheel disposed between the band and the periphery of theshaft is compressed in fitting the wheel on the shaft to thereby securethe wheel on the shaft by an interference fit.

It is also an object of the instant invention to provide -a novel wheeland shaft assembly for a conveyor idler, in which the wheel comprises abody portion and'a hub portion, and in which the wheel is assembled onthe shaft with an interference fit by compression of the material of thehub portion, and the body portion of wheel is maintained in a Stressfree condition to absorb the forces of impact loadings on a beltsupported by the idler.

Other objects of the invention will appear hereinafter, the novelfeatures and combinations being set forth in the appended claims.

In the accompanying drawings:

FIG. 1 is an elervational view of a conveyor idier constructed inaccordance with the instant nvention;

FIG. 2 is a sectional view of the conveyor -idler shown in FIG. l, takenon the line 2-2 in FIG. l; and

FIG. 3 is a sectional view of the wheel and shaft, taken taken on theline 3-3 in FIG. 2.

The conveyor idler 10, seen in FIG. 1 of the drawings, comprises anelongated, hollow shaft 12 and a plurality of laterally spaced wheels 16mounted on the periphery of the shaft 12, fort' supporting a conveyorbelt 11. The elongated, hollow shaft 12 is rotatably supponted at itsopposite ends by anti-friction hearing assemblies, which are placedwithin the erds of the shaft 12 and mounted on non-rotatable endelements 13, which are adapted to be Secured to suitable supportingstands which, in turn, are mounted on the frame of the conveyor. Theends of the shaft 12 also include dir-t protector elements 14 forclosing the ends of the shaft 12 and preventing the entry of dust andother foreign materials into the ends of the hollow shaft 12 and to theantifriction bearings enclosed therein. The end elements 13 and theshafit 12, including the anti-fr-iction bearings, are retained inassembly on a centrally disposed fixed shaft 15. The internalconstruction of the shaft 12 and the hearing assembly is not illustratedin detail herein since it may be of a conventional construction andforms no part of the present invention.

The hollow, elongated shaft lzcarries a plurality of individual,laterally spaced wheels 16 which are assembled on the shaft 12 by beingforce-fitted axially onto the periphery of the shaft 12 to the desredposition alo-ng the length of the shaft 12, and retained in assemblytherewith by an interference fit between the wheels 16 and theperipheral surface of the shaft 12, as will be explained in greaterdetail hereinafter.

In the conveyor to which the instant invention has application aplurality of idlers 10 is employed, and these are spaced along thelength of the conveyor to support the conveyor belt 11 between the headand foot pulleys of the conveyor. At that position on the conveyor where-the materials are loaded onto the conveyor belt 11, the

idlers 10 may be spaced closely adjacent each other so that the wheels16 on the idlers may operate as a cushioning means under the conveyorbelt 11, to prevent damage to the belt 11 due to the impact loadings towhich it is subjected at the loading station. Also, the wheels 16 on thesuccessive idlers 10 may be spaced di'ferentially along the length ofthe shafts 12, so tha-t the conveyorbelt 11 all across its width willengage one or more of the wheels 16, and the contact of the wheels 16with the surface of the conveyor belt 11 will operate to clean the belt'11 in a manner known to the art. The instant inventiorn facilitates theassembly of the wheels 16 on the shaft 12, in that the wheels aresecured in place on the shaft 12 merely by an interference fit of thematerial of the wheels 16 and the peripheral surface of the shaft 12without requiring any special mountng devices, such as collars, screws,etc.

Each of the wheels 16 is of the same Construction, and one such wheel 16is illustrated in detail in FIGS; 2 and 3 of the drawings. In onepreferred embod iment, the wheel 16 may be formed by molding of rubberhaving a ha rdness of approximately 50 durometer, although it will beunderstood by those skilled in the art that the wheel may be formed ofother materials having like suitable characteristics.

The wheel 16 includes a body portion 17 having a sub- .stantially largeradial dimension and a hub portion 13 integral therewith. The hubportion 18 includes an axial bore 19 within which the shaft 12 is placedin assembling the wheel 16 on the shaft 12. A non-extensible, rigid,cylindrical band 21, preferably formed of metal, is embedded within thehuh portion 18 concentrically with the bore 19. A plurality of parallelwalled, aX-ially extending, radial notches 20 are formed in the hubportion 18 and are equally spaced around the bore 19. The nonextensible,rigid band 21 is of smaller axial dimension than the hub portion 18, andthe band 21 is centrally located in an axial direction in the hubportion 18, so that the material of the hub portion 18 extends to eitherside of the band 21. The band 21 is thus embedded within the hub portion18, and in the process of formirg the wheel 16 a bond is formed betweenthe material of the wheel 16 and the sui-faces of the band 21.

The notches 20 extend from the bore 19 radially outwardly to the surfaceof the band 21, and beyond each edge of the band 21 the notches 20extend further into the hub portion 18, forming oflsets 20' which extendradially beyond the band 21. The notches 20 divide that part of the hubportion 18 between the band 21 and the bore 19 into a plurality ofindividual pads 22 which are operative to engage the peripheral surfaceof the shaft 12 when the wheel 16 is assembled on the shaft 12. Theradial dimension of the pads 22 is relatively small compared to theradial dimension of the body portion 17.

The diameter of the bore 19 in the hub portion 18 is slightly smallerthan the external diameter of the hollow shaft 12, in order that thepads 22 around the bore 19 Will have an interference fit With theperipheral surface of theshaft 12. For example, in some of the idlerassemblies that have been made in accordance with this invention, theexternal diameter of the wheel 16 was 6.250", the external diameter ofthe shaf-t 12 was 3.250" and the internal diameter of bore 19 in thewheel 16 was 3.225" (a dierence of .025"); the axial dimension of bore19 of each wheel 16 was 1.125", the axal dimension of the band 21 was625", and the internal diameter of the band 21 was 3.50". y

When the wheels 16 are to be placed upon the shaft 12, a soap solutionon the shaft 12 is employed as a lubricant to reduce the frictionbetween the surfaces of the pads 22 in the bore 1@ and the shaft 12, andthe .wheels 16 are then force-tted axially onto the shaft 12 'to thedesired positions along the length of the shaft 12. In assembling thewheels 16 upon the shaft 12 in this manner, the material of the pads 22between the 'band 21 and the shat 12 is compressed in a radialdirection, and the forces set up thereby operate to retain the wheel 16in assembly with the shaft 12 in the desired position without anyshifting or creeping of the wheel 16 relatively to the shaf-t 12. t

The notches 28, separating the individual pads 22, permitcircumferential fiow of the material of the pads 22, when the pads 22arecompressed in assembling the wheel 16 on the shaft 12. However, dueto the size of the pads 22, some of the material thereof will tend toflow in a radial and axial direction as well, this flow being absorbedin the material of the hub portion 18 on either side of the wheel 16beyond the edges of the band 21. Thus,

with the band 21 being narrower in an axial direction than the hub 18,and with the band 21 being centrally disposed in the hub 18, thestresses set up by the flow of the material in radial and axialdirections, as aforementioned, are directed generally diagonallyupwardly and outwardly from -approximately the edges of the band 21 sothat these stresses are directed away from the body portion 1'7 of thewheel 16, and do not in any way afiect the body portion 17, leaving itin a stress free condition.

The notches 20 are formed with the ofisets 20' at their ends in order tofurther segregate the pads 22 at a depth radially beyond the band 21.This construction provides some added relief from the stresses which areset up in the material of the hub portion 18 due to the compression ofthe pads 22 by permitting flow of material into the ofisets 20'. Withthis construction of the wheel 16 the compressive stresses set up inassembling the wheel 16 on the shaft 12 are isolated in the hub portion18 and not transmitted to the body portion 17 of the wheel 16. This ismaterial to the successful operation of the wheel 16.

It will be understood by those skilled in the art that the idler 10,incorporating the wheels 16 of this invention, is adapted to support theconveyor belt 11 at ,both aloading station, at which the conveyor issubjected to 'severe impact loadings due to the dumping of materialsonto the conveyor belt 11, and also in the run of the conveyor belt 11wherein the load may bounce along as the conveyor belt travels over theidlers 10, again subjecting the belt 11 to impact loadings. The impactloadings on the conveyorbelt 11 are transmitted to the wheels 16 to beabsorbed by the body portion 17 thereof. It is for this reason that thebody portion 17 is made with the relatively large radial dimension andis formed of Shock absorbent material. Further, to increase the usefullife of the wheels 16 it is necessary that the body portion 17 be freeof any internal stresses which would detrimental-ly atfect the shockabsorbing capacity of the body portion 17. In accordance with thisinvention, the stresses which are set up due to the compression of thematerial of the pads 22 are isolated in the hub portion 18, therebyachievng the desirable result of maintaining the body portion 17 free ofinternal Stress, and permitting the forces of the impact loadings to bedistributed in the body portion of the wheel in radal andcircumferential directions.

lt is important to note that the cylindrical band 21 is made of amaterial, preferably metal, which is nonresilient, that is a materialwhich will not Stretch or otherwise become deformed to any materialdegree, whereby the internal diameter of the band 21 will not bematerially altered. It is also very desirable that the band 21 be bondedto the hub portion 18 of the wheel 16, in order that there will be noheat generated within the wheel 16 When it is Operating to carry 'aload, by reason of friction between the rubber of the wheel and thematerial of the band 21. Heat thus generated within a wheel produces adegeneration of the rubber of the wheel, which, of course, is to beavoided.

Prom the foregoing it will be seen that by this invention there has beenprovided an improved idler assembly in which a plurality of improvedindividual wheels are force-fitted upon a shaft, wherein the wheels maybe spaced in any desired positions relatively to each other, and inwhich no special fastening devices or spacers are employed since thewheels are ,retained in position upon the shaft solely by the frictionof the material of the wheel that is compressed between the shaftsurface and a non-extensible, rigid bandembedded in the wheel.

It will also be seen that by this invention there has been provided animproved individual wheel which is adapted to be forced `axially upon ashaft of a conveyor idler assembly, which wheel includes an improvedconstruction in which there is a non-extensible, rigid, cylindrical bandembedded in the material of the hub of the wheel, which band is adap-tedto cooperate with the shaft upon which the wheel is to be force-fitted,to compress the material of the hub, and more specifical'ly the padsformed therein, to fix the wheel upon the shaft.

Obviously those skilled in the art may make various changes in thedetails and arrangement of parts without departing from the spirit andscope of the invention as defined by the claims hereto appended, andapplicant therefore wishes not to he restricted to the preciseconstruction herein disclosed.

Having thus described and shown an embodirnent of the invention, what itis desired to secure by Letters Patent of the United States is:

In `a conveyor having a conveyor belt, a conveyor belt idler comprisinga shaft and a wheel on the shaft for supporting the conveyor belt in itsrun and absorbing impact loadings on the belt, said wheel comprising abody portion of substantial radial depth formed of yieldable material,the belt engaging the periphery of the wheel for transmission of theimpact loadings to the body portion, a hub portion formed integrallywith the body 'portion and having a bore with a diameter which issmaller than the diameter of the shaft for securing the wheel to theshaft by an interference fit between the bore and the shaft, an endlessnon-extensible, rigid band disposed concentrioally with the bore andembedded in the hub portion, said band being narrower in an axialdirection than the hub portion, said hub portion including a pluralityof pads formed between the band and the bore and having inwardly facingsurfaces forrning the bore, said pads being disposed circumferentiallyof the bore, notches extending radially outwardly from the bore to theinner surface of the band and extending the full width of the hubportion to `segregate the pads one from the other, the ends of thenotches beyond the edges of the band being offset radially into the hubportion beyond the plane of the b and, the pads being relatively thin ina radial direction with respect to the depth of the body portion, saidpads being compressed between the shaft and the rigid band, said rigidband isolating the pads from the body portion and thecompressve'stresses free condition for absorbing impact loadings anddistributirg the forces of said impact loadings radially andcircumferentially in the body portion only of the wheel.

References Cited in the file of this patent UNITED STATES PATENTS684,273 Leavenworth Oct. 8, 1901 2,017,149 Greenng Oct. 15, 19352,271,166 Weiss Jan. 27, 1942 2,326,670 Patte-son Aug. 10, 19432,484,752 Searles Oct. 11, 1949 2,701,971 Carter et al Feb. 15, 1955

